7th Shallow Gas Group Meeting Baku, Azerbaijan, – STRUCTURE AND DISTRIBUTION OF GAS HYDRATES IN MARINE SEDIMENTS Contribution 4, by: F. Abegg, G. Bohrmann, GEOMAR J. Freitag & S. Kipfstuhl, AWI

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Introduction Objectives, techniques, working areas Examples of different internal gas hydrate structures Quantification of gas hydrate, free gas and host sediment A frozen core from the Black Sea A pressurised core from Hydrate Ridge Conclusions

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Tool: X-Ray CT scanner

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Frozen gas hydrate sample in a foam box

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Black Sea: core location

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Hydrate Ridge: core location

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Sample SO148-11

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Honeycomb structure 20 mm gas hydrate (light grey) mud (dark grey) carbonate (black spots)

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Sample SO148-20

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Dense gas hydrate 40 mm

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Sample SO148-14

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Alternating layers 50 mm

7th Shallow Gas Group Meeting Baku, Azerbaijan, – SO148-5: 3-D using 227 slices

7th Shallow Gas Group Meeting Baku, Azerbaijan, – SO148-5: 3-D cutout

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Example of thresholding

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Quantification of components Example from sample SO148-11

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Frozen core from the Black Sea

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Various analyses 3-D gas hydrate

7th Shallow Gas Group Meeting Baku, Azerbaijan, – MultiAutoklavCorer

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Pressurised? YES!!

7th Shallow Gas Group Meeting Baku, Azerbaijan, – LabTransferChamber positioned in CT scanner

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Results LTC4

7th Shallow Gas Group Meeting Baku, Azerbaijan, – shell/carbonate gas hydrate gas mud 10 cm subseafloor depth 27 cm subseafloor depth 29 cm subseafloor depth Slices from LTC4

7th Shallow Gas Group Meeting Baku, Azerbaijan, – D and 3-D

7th Shallow Gas Group Meeting Baku, Azerbaijan, – Conclusions CT is an appropriate tool to quantify gas hydrate, gas and host sediment on a mm-scale and to determine internal structures Together with autoclave technology the above is possible close to in situ conditions A frozen core from the Sorokin Trough shows gas hydrates in elongated near-vertical, crack-like features In situ gas hydrate concentration at Hydrate Ridge reaches 50 Vol.% in a horizontal layer with a gas content of up to 10 Vol.% Thank you very much for your attention! respond to: